Commentaries of the Four Authorized Vaisnava Sampradayas

The word upasate means worship. Lord Krishna is explaining that knowledge
of Him as the universal form of all creation and realisation of Him as
paramatma the Supreme Soul in every sentient being is also worship of Him.
Everything is a part of the Supreme Lord Krishna and even knowledge of this
is an oblation and offering to Him in adoration. Some worship the Supreme
Lord as being non-separate from themselves, others worship Him as being
distinctly different thinking He is the Supreme and I am His humble
servant. Still others worship the Supreme Lord Krishna in His guna forms or
manifestations of Brahma and Shiva or any of His other sixfold avatar or
incarnation forms such as Rama, Buddha or Narasimha as well as His
expansions in Vaikuntha the eternal spiritual worlds where He expands
Himself in forms such as Narayana, Sankarsana, Vishnu and Jagannatha.

Brahma Vaisnava Sampradaya:

Madhvacarya

Madhvacarya's Commentary

The Supreme Lord Krishna exists in all places. This means that He is
omnipresent everywhere in a unified manner and it also means that He exists
in special forms authorised in the Vedic scriptures that have extraordinary
attributes and phenomenal qualities. In the Sanat Sujati it is stated: In
the four yugas or ages He is of whitish hue, reddish hue, blackish hue and
golden hue. So the Supreme divinity may be perceived extensively in
unlimited ways at all times as the one as the many and His own personal
distinct forms as well.

Now begins the summation.

The knowledgeable and noble minded worship Lord Krishna in His own
individual two armed form or in His four armed expansion as Narayana the
Lord of Vaikuntha the eternal spiritual worlds. They also may worship Him
as Caturvyuha or His fourfold expansions of Vasudeva, Sankarsana,
Pradyummna and Aniruddha as well as any of the caturvyuha's twenty
expansions such as Keshava or Purusottama from Vasudeva, Govinda and Vishnu
from Sankarsana, Narasimha and Vamana from Pradyumna and Hari and Damodara
from Aniruddha. They may also worship Him as any of His sixfold
incarnations being Purusa Avatars, Lila Avatars, Guna Avatars, ManvantaraAvatars, Satyavesha Avatars and Yuga Avatars.

Sri Vaisnava Sampradaya:

Ramanuja

Ramanuja's Commentary

The mahatmanas or those of great souls discuss, sing and reflect on the
glories of Lord Krishna without abatement in what is called jnana yagnena
or propitiation by knowledge. How is this to understand? By constant
meditation of Him as the unity comprising the infinite variations of
unlimited diversity displayed in creation as the form of the cosmos. The
essence of understanding this phenomena is as follows. The Supreme Lord
Krishna alone is the sum total of all having within His spiritual body the
most fine and supra subtle state chit or the principles of consciousness
and also that of achit or inconsciousness without names, forms and
distinctness. By His indomitable will the Supreme Lord resolves to manifest
from His spiritual body consciousness and inconsciousness into their
relative material states having names, forms and distinctness. Thus the
Supreme Lord Himself being the totality of all is perceived in His
manifested cosmic form exhibiting the marvelous variegations of existence
such as the heavenly demigods, humans, flora, fauna and aquatic as well as
the stationary kingdoms. Contemplating the Supreme Lord as all inclusive
they are worshipping Him. Therefore He is declared to be the universal
form.

Kumara Vaisnava Sampradaya:

Nimbaditya

Kesava Kasmiri's Commentary

The most excellent mahatmanas or great noble souls worship the Supreme Lord
Krishna by jnana yagnena or propitiation by knowledge. Other mahatmanas
chant His names and glories and also by propitiation of knowledge offering
worship to Him in His universal cosmic form facing all directions in all
locations as the all pervasive paramatma or supreme soul within all living
entities. In the Chandogya Upanisad III.XIV.I it states: Verily the whole
creation is brahman or the Supreme Lord's spiritual substratum pervading
all existence. Tranquilly one should worship it as the source from whence
one came forth, as that source to where one will go hence and as that in
which one breathes. All creation is verily the paramatma of the Supreme
Lord Krishna. Everything is Lord Krishna, He is omnipresent, the highest
person, the one and only Supreme Lord. He is realised as the universal
cosmic form of all existence comprised of phenomenally unlimited variations
of all animate and inanimate beings. The Katha Upanisad V.XIII states: The
Supreme Lord who is constant among the inconstant, intelligent among
intelligences, the one among the many, who grants desires. In the
Brhadaranyaka Upanisad III.VII.II states: That he who dwells in the earth
does not know whose body the Earth is or who controls the Earth from within
is the atma or immortal soul, the inner monitor and controller. The Katha
Upanisad V.X.XI states: As one wind has entered the world and becomes
corresponding in form to every form, so the one inner atma of all things is
corresponding in form to every form and yet is separate from them. As the
sun which is the eye of the universe shining upon everything is not
compromised by the external faults of the eyes; in the same way the
immortal soul of all beings is not compromised by the evil manifesting in
the world, being external to it. Thus the most excellent great souls
worship the Supreme Lord Krishna as totally different from this universe
comprised of animate and inanimate beings because although He is within all
various diverse and variegated forms as paramatma He is completely
unaffected by them.